Process of preparing wood-alcohol and chloroform.



HABRYo. GHUTE, or CLEVELAND, oHIo.

PROCESS OF PREPARING WOOD-ALCOHOL AND GH'LOROFORML Specification ofLetters Patent.

Patented July 21, 1908.

Application filed October 6, 1903. Serial No. 175,726.

' To all whom it may concern:

citizen of the United States, and a resident of Cleveland, in the countyof Cuyahoga and State of Ohio, have invented a new and Improved Processof Preparing wood Alcohol and Chloroform, of which the following is afull, clear, and exact description.

This invention relates to processes of preparing wood alcohol andchloroform; and com rises a method wherein pure wood or met yl alcoholand chloroform are separated from each other by fractional distillationfrom a'mixture of the same after addition to such mixture of one or morebodies having the property of raising the boiling point of such methylalcohol and wherein such a mixture is produced by treating ordinarycrude wood spirit with rea ents adapted to form chloroform therein; a las more fully hereinafter set forth and as claimed.

Ordinary crude wood spirit, or the spirit-' uous roduct from thedestructive distillation of wood and woody fiber, consists essentiallyof a mixture of methyl alcohol, acetone and other ketones, and otherimpurities, all admixed with more or less water. Preparation of puremethyl alcohol from this crude wood spirit by the ordinary methods offractional distillation is a diflicult, tedious and expensive operation,the boiling oints of the alcohol and of acetone lying not ar apart, withthose of other ketones and impurities intermediate. For this reason pureacetonefree methyl alcohol is unduly expensive in commerce.

By treatment of wood alcohol with neutral or alkaline hypochlorites, theacetone and some of the other impurities are chan ed into chloroform,leaving the methyl alco o1 unaltered, provided there is no excess ofhyochlorite added. This is not in itself a useul reaction, so far asprevious knowledge has gone, for it is diflicult to separate thesebodies by fractional distillation, the boiling oint of methyl alcohol,66 0., not being far from that of chloroform, 61 C.

I have discovered that the addition of water or of soluble orhygroscopic salts, or of both, converts this reaction mixture into onefrom which the constituents can be easily separated. Water and such,salts possess a physical aflinity for methyl alcohol and raise itsboiling point material while having no such effect u on chloroform,chloroform being immiscilile with water and dissolving few or none ofthe ordinary metallic salts. Such an addition of water or soluble saltsto the reaction mixture tends to make the chloroform se arate physicallfrom the methyl alcohol. ile nearly a soluble salts have this effect,the ordinary hygrosco ic salts have it in an enhanced degree, nearl yall hygrosco ic salts being quite soluble in methyl alcoho and itsaqueous solutions. Using water alone, I find a useful degree of dilutionto be thatwhich will give an apparent alcoholic strength to the reactionmixture of about 50 er cent, although of course a greater or ess degreemay be em loyed. A dilution at which the mixture will have such aspecific gravity that upon spindlin with an or inary alcohol hydrometerit will show a reading of-about 50 per cent. alcohol is well ada tedhowever to the present purposes.

A most any of the ordinary soluble or hygroscopic salts may be employed;such as, for instance, potassium chlorid, potassium nitrate, potassiumacetate, sodium chlorid, sodium nitrate, sodium acetate and similarsalts of magnesium, calcium, barium, strontium and zinc. Of these salts,I prefer cal cium chlorid as bein cheap, effective and easilyregenerated. n employing ordinary bleaching powder, or calciumhypochlorite,

to form a mixture of methyl alcohol and chloroform from crude woodspirit more or less calcium chlorid is formed in the reaction mixture.Where both water and salts are employed to raise the boiling point ofmethyl alcohol, the amount of water may be diminished to correspond withthe amount of salts present; 5'to 10 per cent. of calcium chlorid, forinstance, -being used with a solution having an apparent alcoholic tenorof per cent.

' In treating w'ood spirit with hypochlorites, ordinarily I prefer touse the calcium salt, or ordinary bleaching powder, as the cheapest, butother hypochlorites such as those of sodium or potassium, may beemployed. It is not necessary that the hypochlorite be preformed sinceit can be generated in the reaction liquor itself, as by introducingchlorin after making such liquor alkaline. It is important that thehypochlorite shall be present ina neutral or alkaline liquor, as hyochlorites cannot exist in the resence of ree acid but evolve chlorin. Clorin does not form chloroform but produces chlor-acetones, bodies ofhigher boiling point and piercing odor. The reaction mixture containingthe hypochlorite should be heated.

Since wood spirit contains other bodies than acetone capable of reactingwith hypochlorites, it is generally desirable only to add the amount ofsuch hypochlorite ca able of reacting with such acetone, there y botheconomizin hypochlorite and securing purer roducts. l or this urposeadvantage may e taken of the Wea (er afiinity of iodin for these otherbodies. A measured portion of the Wood spirit to be treated ma haveadded to it an amount of potassium io id more than is equivalent to theamount of acetone likely to be present. Upon nowgradually adding a hyochlorite solution of known strength, the iodin and acetone react toform iodoform and at the moment when the acetone all disappears, freeiodin will be liberated and may be detected. The amount of hy ochloritenecessary to produce this result is t lie most advanta eous amount withwhich to treat the particular wood spirit under examination. Or, 'afteradding the potassium iodid an excess of hypochlorite may be added andthe freed iodin titrated back in the ordinary manner, the amount of suchiodin corresponding to the excess of h ochlorite which was employed.Upon ad 'ng the determined amount of hypochlorite to a particular sampleof wood s irit, the acetone and other chlorofornryiel ing ketones andbodies are converted while the remainin constituents are not acted on toany substantial extent.

"Briefly stated, my new rocess consists in treating wood spirit witadding a substance which has su cient affinity for methyl alcohol tohold it back in distillation and distilling off the chloroform, eitherwhile the chloroform-producing reaction is progressing, or later. Thechloroform distilsover containing but little alcohol and from thissmallportion it may be; separated by addition of Water or salinesolutions, the aqueous liquid se arated being. redistilled to re ain any0 oroform therein contained. After distilling off the chloroform fromthe original liquid, the methyl alcohol may be distilled over inturn'and rectified in any of the well-known wa' s. It is now free ofacetone and similar oxidizable ketonic imurities. A mixture of alcoholand chloroorm, such as is roduced in treatin crude wood spirit with Withwater or a saine solution containing a hygiochlorite;

ochlorite, upon ilution.

water yields its chloroform to distillation first and any such mixturemay of course be treated by'the described rocess.

As an example 0 my process in treating wood spirit, I may run, say, 300gallons of wood spirit into a still of 1,000 gallons capacity. The sirit should preferably show an apparent acoholic readin of about 95 ercent. on a Tralles alcoho ometer. The

ralles scale is designed for grain alcohol but the specific gravities ofmethyl alcohol and acetone solutions are about the same as those ofgrain alcohol. The spiritin the still is then heated and a solution orpasty mixture containing the amount of hypochlorite determined in thedescribed manner as re uired for that particular spirit, is next adde Asthe reaction of the hypochlorite upon the wood spirit evolves heat, careshould be taken to prevent too violent an action, as in this event someof the methyl alcohol might ,be destroyed. When the action slackens,'water is added in amount suflicient' to give the liquid an apparentalcoholic strength of about 50 per cent. and heat is applied to distiloff the chloroform which has been produced. As long as the distillateupon the addition of'water shows the presence of chloroform b forming aheavy underlying layer, the disti late is caught in as ecial chloroformreceiver. When chloro orm will no lon er se arate, the distillation iscontinued an the istillate received in a tank for purified methylalcohol.

Having thus described my invention,

what I claim is 1. The process of purifying Wood spirit which consistsin treatlng wood spirit Wltllfi. hypochlorite to; form chloroform fromthe ketonic im urities, adding 'a-body' having sufficient a 'tyformethyl alcohol to raise its boiling point and distilling off thechloroform.

2. The process of purifying wood spirit which consists in treatln woodspirit with a hypochlorite to form 0 loroform, diluting the reactionmixture with water and distilling off the chloroform.

3. The process of urifying Wood spirit and producing chloro orm whichconsists in treatlng acetone-containin wood spirit with a-hypochloriteto form chloroform, diluting the -reaction mixture with water and asalt, and distilling ofi the chloroform.

4. In the process of making pure methyl alcohol and chloroform, themethod which consists in adding to a mixture of methyl alcohol andchloroform a bodyhaving suflicient afiinity for meth 1 alcohol to raiseits boiling point and in -t en distilling off the chloroform.

5. In the process of purifying methyl aleohol and making chloroform, themethod which consists in diluting admixture of methyl In testimonywhereof I have signed my alcohol and chloroformwith water and disname tothis specification in the presence of 10 tilling off the chloroform. 1two Witnesses.

6. In the process of purifying methyl a cohol and -producin chloroform,the method U which consists in di uting amixture of methyl Witnesses:alcohol and chloroform with water contain- H. L. PAYNE,

ing a salt and distilling off the chloroform. W. P. JOHNSON.

